Not sure where we're supposed to leave the feedback you (kinggath) asked for on this patch so I guess I'll put it here?
I excitedly rebuilt the Max Shack I had torn down in frustration awhile back only to run into exactly the same navigation problems I was having before -- in fact seemingly worse. The settler would work at her job plot fine, but once she was supposed to go to bed she would just stand in place. If I manually tried to move her into the house she would ignore the stairs leading to the front door and instead go up the stairs of the plot next door, getting stuck on the mailbox there. If I tried to reassign her to the Shack she would leave and walk out to the default spot of the settlement (Starlight) and stand there. By "default" here I mean that place that the navigational icon representing the settlement is placed on your PipBoy, which also seems to be where you'll occasionally get your settlers spawning in before the scripts catch up and they start moving off to do their jobs.
So I'd observed all this frustrating behavior before and 2.1.7 didn't seem to change it at all, even after multiple reloads, refreshes and even scrap and rebuilds. I gave up for the night.
I planned to write expressing that 2.1.7's Max Shack upgrade had apparently failed but before I did so today I started the game and tried one more complete plot refresh, and wonder of wonders, I watched her finish her work for the day, walk across the lot, up another set of stairs I made (which she ignored before), went in, went right up those cramped stairs inside the shack, and got into bed. Didn't even have to teleport.
So, okay. I'm giddy. I don't know what it was I had to tweak on my end before the new pathing took effect but whatever you did worked!
Here's hoping it stays stable. Today I'm going to check on my Max Shack over in Sanctuary and see if the settler there is also finding her bed, then I'll adventure around a bit and try building and assigning one in a new area.
Fingers crossed.